Numerical modeling of elastic energy accumulation and release in structurally heterogeneous geomaterials

The approach to numerical modeling of specimen loading considered by the authors using the discrete element method enables describing ability of rocks to accumulate and release elastic energy. The model specimen is a package of particles characterized by viscoelastic interaction with dry friction. The outer layer particles are connected by elastic springs. On the whole, the model specimen is an element of a medium capable of accumulating a part of energy of deformation in the form of internal self-balanced stresses. Numerical modeling of the specimen compression is performed, and the accumulated energy is assessed. It is shown that clusters form in the medium, and sliding along the boundaries of these clusters causes discontinuities in deformation curve. Also, the discontinuities are possible under stress relaxation after unitary dynamic effect on the specimen. There is a good agreement between the numerical and experimental results.